The FBI and police in California are searching for a woman who styles herself as a countess and is alleged to have tried to con investors out of billions of dollars by pretending to be a member of the illustrious Guggenheim family.

Catarina Pietra Toumei Toumei, 45, is alleged to have been one of three grifters who posed as members of the family best known for their art galleries in New York, Los Angeles, Bilbao and elsewhere.

The three attempted to sell $1bn of diamonds "from the private collection of the Guggenheim family", a batch of "Guggenheim Vodka", and $4bn worth of crude oil from a Guggenheim-owned refinery in China, it is alleged.

Two men are in custody, accused by a New York prosecutor of posing as David B Guggenheim and Vladimir Guggenheim. They are said to be in reality David Birnbaum from Brooklyn, 67, and Vladimir Zuravel, 45, from Queens.

"The defendants allegedly impersonated one of America's most famous families to fleece potential victims by pitching bogus investments," the prosecutor, Preet Bharara, said.

It is not known whether anyone did fall for the con, but the three targets who agreed to work with prosecutors to uncover and arrest the trio allegedly responsible did not lose any investments in the process.

Police were directed to the scam by the real Guggenheim family which, through the medium of their investment firm, Guggenheim Capital, sued the alleged fraudsters for having misused their good name.

The Guggenheim family made its fortune in mining and smelting, but has been best known in recent years for its philanthropy in the arts.